The present invention relates to a steering assist apparatus, and more particularly to an apparatus for assisting a steering wheel operation in parking.
Conventionally, an apparatus has been proposed which displays a rear side view of a vehicle on a monitor in the case where the target place is out of sight from a driver due to the dead angle of the vehicle when the vehicle reverses. For example, Japanese Patent Examined Publication No. 2-36417 discloses a rear view monitoring apparatus for a vehicle which comprises a television camera for picking up a rear view of the vehicle, a monitor television set for imaging an image picked up by the camera, a sensor for outputting an information signal related to a tire steering angle and a circuit for generating a marker signal in response to the information signal from this sensor and superimposing the marker on the television image field. In this apparatus, the tire steering angle data and the marker position data along the reverse direction of the vehicle corresponding to its steering angle are stored in a ROM, and a predicted reverse locus of the vehicle in correspondence with the steering angle at that time is superimposed and displayed on the image picked up by the television camera on the television view field as a row of the markers.
By such an apparatus, since the predicted reverse locus of the vehicle in correspondence with the steering angle together with the view field of the conditions of the road on the rear side is shown on the image field of the monitor television when the vehicle reverses, the driver may reverse the vehicle by manipulating the steering wheel while watching the television image field without looking back.
However, such a conventional apparatus is simply an apparatus that shows the relationship between a hindrance on the rear side of the vehicle and the predicted reverse locus by showing the predicted reverse locus of the vehicle and provides reference information to the driver as to whether the vehicle may avoid the hindrance or not.
In the case where the vehicle is to be parked in parallel, parking the vehicle suitably in a parking space without finely adjusting the steering wheel steering amount during the reverse motion leads to the possibility that the driver may park the vehicle in parallel with paying his or her attention to the outside of the vehicle without being nervous about the steering wheel operation. This is one of the important advantages for the suitably parking the vehicle in parallel. However, the conventional rear view monitoring apparatus involves a problem that it is difficult for the driver to judge where the steering wheel should start to be operated and how much the steering wheel should be operated to park the vehicle suitably in the parking space without finely adjusting the steering wheel steering amount when the vehicle reverses in the case where the vehicle is close to the parking space in which the vehicle is to be parked in parallel. Thus, it is impossible to sufficiently assist the driver for the suitable parallel parking by the conventional rear view monitoring apparatus.
In the case where the vehicle is to be parked in line, for example, the vehicle is reversed in parallel with a road, the vehicle is entered into a parking space by operating the steering wheel at a suitable position, and the vehicle is guided into the target parking position by turning the steering wheel in the reverse direction. However, in the conventional rear view monitoring apparatus, only with the driver viewing the predicted reverse locus of the vehicle and the rear view field on the television image field, it is difficult for the driver to judge where the steering wheel should start to be operated, where the steering wheel should be turned and how much the steering wheel steering amount should be selected. Accordingly, if it is possible to know the operation timing or the specific operation method in response to the position of the vehicle, it is possible even for the driver who is not familiar with the operation to easily operate the steering wheel. Also, if the steering information may be also obtained from other than the television image field, it is unnecessary for the driver to watch continually the television image field and it is preferable for the driver to see the outside of the vehicle.
In view of the foregoing defects, an object of the present invention is to provide a steering assist apparatus by which the driver may readily recognize the steering timing when the driver parks the vehicle.
Another object of the invention is to provide a steering assist apparatus by which the driver may readily recognize the steering amount that is needed for parking.
According to a first aspect of the invention, there is provided a steering assist apparatus comprising: a camera for picking up the rear side of a vehicle; a monitor disposed in a driver""s compartment of the vehicle; a steering angle sensor for detecting a steering angle of a steering wheel; and a display controlling means for displaying an image through the camera on the monitor when the vehicle reverses and for superimposing and displaying a guide display on the monitor for assisting the drive of the vehicle during parking, wherein the guide display includes a steering start guide line fixedly displayed in a predetermined position of an image field of the monitor for guiding a steering start position for parking, and a steering amount guide mark moved and displayed along the steering start guide line on the image field of the monitor in correspondence with a steering angle of the steering wheel detected by the steering angle sensor.
According to a second aspect of the invention, there is provided a steering assist apparatus for assisting a steering operation when a vehicle is reversed to be parked, comprising a yaw angle detecting means for detecting a yaw angle of the vehicle, a reference setting means for setting a zero position of the yaw angle, a steering angle sensor for detecting a steering angle of a steering wheel, and a guide means for identifying a position of the vehicle in accordance with the steering angle detected by the steering angle sensor and the yaw angle detected by the yaw angle detecting means and for providing steering information to the driver.